Composition of matter



Pat nted Feb. 21, 1939 r I. 2 148 325.

UNITED STATES PATENT OFFICE COMPOSITION OF MATTER Augusto Schwind, Buenos Aires, Argentina No Drawing. Application March 5, 1937, Serial No. 129,282. In Argentina January 5, 1937 10 Claims. (01. 1062) This invention relates to the manufacture of tinguished by the nature of the fracture on accumulator casings and the like. The word breakage and by the smell given off from fresh casing in this specification is intended to infractures.

clude also the covers and stoppers used for the Although I have found that resin-free vege- I 5 closures of certain types of accumulators or for table pitches give satisfactory results when in- 5 closing the filler openings. corporated in a moulding composition as indi-.

The object of the present invention is to procated above, the mechanical strength of the revide a composition of matter for the manufacture sulting moulded product may be further imby moulding under pressure of the said cases, proved by adding to the composition .a proporsaid composition of matter having certain novel tion of a polymerized syntheticresin. 10 and advantageous features. A vegetable pitch capable of resisting for an Hitherto various types of mixtures and comindefinite time the action of a solution ofsulpositions for such purpose have been proposed, phuric acid of specific gravity 1.3 at temperaincluding mixtures having tar, pitch or bitumen tures between 40 and 45 C. (which conditions as their principal component, but heretofore such hold in motor-car accumulators) is obtained by 5 principal component has always been of mineral selecting preferably pitches derived from nonorigin. Such materials have, however, a natural coniferous trees, as already indicated,'since these tendency to adhere to the tools and moulds durpitches are in themselves either free of natural ing the process of manufacture and are, furtherresins or contain very small quantities thereof.

more, not capable of offering a satisfactory resist- I prefer to use pitches the melting point of which 20 ence to continued attack by sulphuric acid. If is in the neighbourhood of 100 C. Such pitches such materials are treated to remove their tendrepresent the residues of distillation carried to ency tostick, they have been found to become the point at which'the properties of the residues very brittle. comply with the requirements outlined above.

I have discovered that vegetable pitch, and Of the pitches derived from non-coniferous 26 particularly pitch derived from non-coniferous trees, the pitch obtained from beech-wood as a trees, has properties which permit of its use as residue after all harmful or undesirable matethe base of a moulding composition for the manurials have been driven ofl, lends itself excellently facture of accumulator casings and the like, with to the manufacture of accumulator casings and considerable advantages both as regards the acthe like. tual manufacture and the finished product. As already stated, I prefer to use residues hav- Such pitches are free from fats and, preferably, ing a melting point in the neighbourhood of 100 those are selected for my composition of matter, 0., but the present invention is not to be conwhich contain little or no natural resin. The sidered as limited to this figure, since the meltmost important property of these vegetable ing point should be selected by those skilled in the 5 pitches, however, is that they can be treated to art to meet the requirements imposed by the remove any natural resin they may contain, and conditions under which the finished product is thereby to render them non-sticky, without causto be used. ing them to become brittle. A further advantage My novel composition of matter may suitably 4.0 of these pitches is that if for any reason they be made up as follows: become carbonized, the resultant mass is a non- P r t conductor of electricity, Whereas the mineral Vegetable pitch 40-60 pitches and the like, become conductive on car- Silicates 20-40 bcnization. Fibrous material 8-28 The vegetable pitches referred to are, according to the present invention, mixed with a filler, preferably a silicate filler, and an inorganic or If synthetic resin is added the above formula is modified as under:

Per cent organic fibrous binder, glving a composition v which may be moulded when hot, to form casings gfifiii which are found to be highly resistant to the Fibrous 50 action of sulphuric acid. The casings thus synthetic resin 10 35 formed have likewise a high mechanical strength and an appearance similar to that of casings As filler, any silicate may be used which is an made of vulcanized rubber or mineral pitches, electrical insulator, is water-repellent and unfrom which however, they are readily disattacked by sulphuric acid, as for example tale. 5

The fibrous material may, as already stated, be inorganic (asbestos) or organic (cotton, horsehair, wool and the like) or a mixture of organic and inorganic fibres. When a synthetic resin is added this should preferably be a condensation product capable of being melted and remelted, so as not to affect adversely the property which my composition of matter has, of being capable of being remelted after it has once been pressed.

The ingredients are mixed hot in a mixer until a homogeneous paste is formed. This paste may, if necessary, be stored in heated and closed kettles until required. The amount necessary to form the casing it is desired to make is taken and kneaded and/or rolled under conditions whereby loss of heat is avoided, whereupon the said amount is introduced in a mould adapted to be heated and cooled, and moulded under pressure. When the mould has been cooled the finished casing is withdrawn therefrom.

As has already been indicated, the casings made from the composition of matter according to this invention and by the method briefly described do not stick to the mould or to the die during the pressing. They are resistant to acids, photochemical effects and mechanical damage. They give a somewhat metallic ring and possess relatively high coefficients of resistance to compression and hardness.

I claim:

1. A composition of matter for the manufacture by moulding under pressure of casings, covers and stoppers for electric accumulators, which comprises a mixture of vegetable pitch derived from wood free from natural resins, a fibrous binder and a silicate filler.

2. A composition of matter for the manufacture by moulding under pressure of casings, covers and stoppers for electric accumulators comprising a mixture of a vegetable pitch derived from non-coniferous trees and free from natural resins, a fibrous binder and a silicate filler.

3. A composition of matter for the manufacture by moulding under pressure of casings, covers and stoppers for electric accumulators comprising a mixture of beechwood pitch free from natural resins, a fibrous binder and a silicate filler.

4. A composition of matter for the manufacture by moulding under pressure of casings, covers and stoppers for electric accumulators comprising a mixture of a vegetable pitch derived from wood free from natural resins, a fibrous binder and tale.

5. A composition of matter for the manufacture by moulding under pressure of casings, covers and stoppers for electric accumulators, comprising a mixture of a vegetable pitch derived from wood free from natural resins, an organic fibrous binder and a silicate filler.

6. A composition of matter for the manufacture by moulding under pressure of casings, covers and stoppers for electric accumulators, comprising a vegetable pitch derived from wood free from natural resins, an inorganic fibrous binder and a silicate filler.

'7. A composition of matter for the manufacture by moulding under pressure of casings, covers and stoppers for electric accumulators comprising a vegetable pitch derived from wood free from natural resins, a fibrous binder, a silicate filler and a polymerized synthetic resin.

8. A composition of matter for the manufacture by moulding under pressure of casings, covers and stoppers for electric accumulators comprising a vegetable pitch derived from wood free from natural resins, a fibrous binder, a silicate filler and a fusible and refusible synthetic resin.

9. A composition of matter for the manufacture by moulding under pressure of casings, covers and stoppers for electric accumulators comprising.

Per cent Vegetable pitch derived from wood free from natural resins 40-60 Silicates 20-40 Fibrous material 8-28 10. A composition of matter for the manufacture by moulding under pressure of casings, covers and stoppers for electric accumulators comprising:

AUGUSTO SCHWIND. 

